Emissions from an internal combustion engine can be significantly affected by the operating temperature of the engine. If a faulty thermostat is stuck in an open position, excess undesirable emissions can result due to an extended warm up period for the engine. Alternatively, if too many heat exchangers that exchange heat with engine coolant are added to a final machine, the engine might also warm up slowly. In extreme situations the engine may not be able to warm up completely to normal operating temperatures. An overcooled vehicle configuration may be misdiagnosed as a thermostat failure.
The present disclosure is directed to one or more of the problems set forth above.